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Biomedical subjects

H Shibata

Publications and source records attributed to H Shibata.

At least 811 records · Page 45Linked to original sources
PubMed1979

Presence of mast cell precursors in peripheral blood of mice demonstrated by parabiosis.

The presence of mast cell precursors in peripheral blood was examined. The beige C57BL/6 (bgj/bgj, Chediak-Higashi syndrome) mouse was parabiosed with the normal C57BL/6 mouse. Mast cells containing giant granules and originating in the beige partner appeared in the normal parabiont. A comparable proportion of normal-mouse-type mast cells developed in the beige parabiont as well. In spite of the low radiosensitivity of mature mast cells, irradiation of the normal parabiont reduced the proportion of normal-mouse-type mast cells appearing in the beige partner. It was concluded, therefore, that the precursors of mast cells can migrate through the bloodstream.

Animals↗
PubMed1978

Inhibition by ammonium ion of germination of unactivated spores of Bacillus cereus T induced by l-alanine and inosine.

Studies were carried out on the inhibitory effect of NH4+ on germination of spores of Bacillus cereus T induced by L-alanine and inosine. Kinetic analysis showed that NH4+ inhibited the germination competitively. Its inhibitory effect was greater when the unactivated spores had been preincubated with L-alanine. NH4+ did not inhibit the response of unactivated spores to L-alanine during preincubation. These results suggest that L-alanine sensitizes the spores to the inhibitory effect of NH4+.

Alanine↗
PubMed1978

Inhibition by potassium ion of the pregerminative response to L-alanine of unactivated spores of Bacillus cereus T.

The effect of potassium ion on L-alanine-inosine-induced germination of unactivated spores of Bacillus cereus T was studied. Unactivated spores germinated in 0.1 M sodium phosphate buffer (NaPB), but not 0.1 M potassium phosphate buffer (KPB), at pH 8.0 and at 30 C. Inhibition of germination was also observed on incubation of unactivated spores in NaPB containing potassium chloride. Previously it was demonstrated that germination of unactivated spores involves at least two steps, one induced by L-alanine, and the other by inosine. Potassium ion seems to inhibit the response of the spores to inosine, because: (1) Spores that had been preincubated with L-alanine in NaPB or KPB, germinated in NaPB but not KPB in the presence of inosine. (2) During germination in NaPB, incorporation of L-[14C]alanine showed bimodal kinetics with a rapid first phase and a second continuous phase, but in KPB the second phase of incorporation did not occur. The events occurring before germination of unactivated spores are discussed with reference to the initiation of germination.

Alanine↗
PubMed1977

Congenital heart disease in high school and college students.

The prevalence and relative frequency of congenital heart disease in high school and college students were investigated during the period April 1970-March 1976. Forty congenital lesions were found among 13,127 subjects which shows a rate of 3 per thousand. The ratio of congenital lesion to rheumatic heart disease was 4/1. Ventricular septal defect was the most common defect, found in 30% of all lesions followed by atrial septal defect (20%) and patent ductus arteriosus (17.5%). The prevalence and relative frequency in those investigated differed only slightly from the results obtained among children. The possibility of spontaneous closure of ventricular septal defect during adulthood strongly suggested itself when compared with our previous data on post middle age subjects.

Adolescent↗
PubMed1977

[Correlation between gastrointestinal absorption and uptake of radioisotopes by the critical organs].

This study was undertaken to investigate the correlation between gastrointestinal absorption of radioisotopes and uptake by the critical organ during the same period using 85Sr, 109Cd, 131I and 203Hg as radioisotopes. When the distribution of 85Sr, 109Cd, 131I and 203Hg in mice were investigated by means of the whole body autoradiography, these critical organs were determined as follows; 85Sr: bone, 109Cd: liver, 131I: thyroid gland and 230Hg: kidney. When the correlation between the injected dose and the uptake dose by the critical organ of 85Sr, 109Cd, 131I and 203Hg were investigated, uptake dose the critical organ expressed as cpm per gram of organ was in direct proportion to the injected dose and that expressed as % of the injected dose per gram of organ was held constand in either case. When the coefficient of correlation between gastrointestinal absorption and uptake by the critical organ of 85Sr, 109Cd, 131I and 203Hg were calculated, a positive correlation was revealed in either case. It is concluded from the results obtained that in vivo or in situ method, gastrointestinal absorption of radioisotopes received a support from uptake by the critical organ during the same period.

Animals↗